US1131707A - Valve mechanism. - Google Patents

Description

C. L. JOHNSON.

VALVE MBOHANISM.

APPLICATION FILED JULY 27, 1914. 1,131,707, Patented Ma1t16, 1915.

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Illlli'l C. L. JOHNSON.

VALVE MBCHANISM.

APPLICATION FILED JULY 27, 1914,

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Patented Mar. 16, 1915.

WEF STATES @FFF@itO VALVE MECHANISM.

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Specification of `Letters Patent.

I Patented Mar. 16,' digiti.

Application iled July 27, 1914. .Serial No. 853,424.

To all whom 'it may concern:

Be it known that l, CLINTON L. JOHNSON, a .citizen of the United States, residing at Rockford in the county of Winnebago and State of Illinois, have invented` certain new and useful Improvements in Valve Mechanism, of which the following is a spec-ifica-` tion.

This invention, while pertaining to valves in general, relates more particularly to the inletand exhaust valves of a gas engine, and to the mechanism for operating the same. The ordinary reciprocating or puppet valves, which are customarily used on gas engines, are open to the objection that the gases pass directly across the faces of the valves and across'the faces of the seats,

with Vthe result that the valves and seats become burned and pitted, and also collect on their working surfaces quantities of carbon and other deposits which are `packed in position by repeated impacts of the valves against their seats, and are burned onto :the surfaces sothat the valves are prevented from seating properly. The sliding or ring valves, commonly known as the Knight valves, are also prone to cake with carbon deposits which seriously interfere with the proper working of the valves and with the eiciency of rthe engine. Furthermore, in

these valves the rings are constantly mov-v ing, so that an accurate t between two sliding surfaces must vbe relied upon to prevent leakage during the compression stroke. rll`he result .of this construction that slight' 'wearing of the contacting sllding surfaces will cause leakage. The other types of con.

tinuously-rotating valves which have been used to a limited extentare also open to the same objections as above noted in connection with the sliding valves. v

My present invention is deslgned to provide a valve which will embody. in one structure both the intake and exhaust valve, and which will overcome the objectionable features of the other types of valves now in use.

With this end in view l have devised a valve, one of the primary objects of which is an intermittent oscillatory movement which will cause the valves to grind their own seats, thereby reducing the liability of l leakage to a minimum.

Another object of the invention is the provision of a valve mechanism in which both the intake and exhaust valves will be stationary during the compression and r- 4vention should be readily understood.

ing'strokes, thereby eliminating friction-and the liability of leakage which occurs inl valves ofthe continuously moving type.

A. further object of the inventionl is to provide va valve structure' whichV will utilize the pressure in the cylinders to maintainthe valves pro erly seated during the compression and ring strokes.

Another object is the provision of novel mechanism for operating the valves, so that the inlet port will be open during the whole intake stroke, and the outlet port will be open during the whole exhaust stroke, while Referring .to the drawlngs: Figure-l is a plan view of a cylinder headl equipped with my invention, this view bein taken on the line l--l of Fig. 4;. Fig. 2 is an elevation looking at one side of the structure shown in Fig. l. Fig. 3 is a sectional view on the line of Fig. 4. Fig. 4r is a sectional view on vthe line lf-4c of Fig.' l. Fig. 5 is a similar view .on the line 5-5 of Fig. 1. Fig. 6 is e' perspectiveview showing the' valve disks as drawn downwardly `from the cylinder head, and showing the position of the parts dur-- ing the intake stroke. Fig. 7 is a similar View showing the'posi'tion of the parte during the compression` and firing strokes, and Fig. 8 is a similar view .showing the osition of the parts during the exhaust stro e.

@n the vdrawings reference character llll. indicates a cylinder head ofthe general type known'as a lf-head motor, the cylinder walls 12, being of any preferred construction. The head 1l is provided with the.

usual intake passage sage le.

,'llhe valves proper, which ll will designate as a and b res ectively, are of disk shape, adapted to he disposed and operate in a deep lf3, and exhaust pae-A cushion or recess 15, formed in the lower face of the cylinder head, the bottom of the recess being machined to provide a bearing face 16 provided with inlet and exhaust jects upwardly through a suitable bearing opening 21 in the cylinder head, and is made hollow to accommodate the stem 22 of valve b, which projects upwardly therethrough. The lower face of valve b is also preferably conical in shape, to present a maximum surface to the pressure within the cylinder, which serves to hold both valves against their seats, thereby preventing leakage.

The disk portions of the valves a and are substantially identical, the valve a being provided with inlet and outlet ports 23 and 24, and the disk b being provided with inlet and outlet ports 25 and 26. When the valves are in their normal or closed positions during the compression and firing strokes, the port 24 is in alinement with port 18, and port 25 is in alinement with port 17. Port 17, however, vis closed by the solid portion of valve a, and port 24 is closed by the solid portion of valve b, allas shown in Fig..7. Just prior to the suction stroke the valve disks a and b" are in the positions shown in Fig. 7 in which both of the fixed ports 17 and 18 are blanked. During the first half of the suction stroke the disk a is turned counter-clockwise through a quarter turn, bringing port 23 into full registration with ports 17 and 25 as shown in Fig. 6. During the last half of the suction stroke, the disk a is turned clockwise back to itsY former position shown in Fig. 7, so that at Ythe end of the suction stroke both ports 17 and 18 are blanked. During the compression and firing strokes both disks remain stationary in the position shown in Fig. 7. During the rst half of 'the exhaust stroke the disk b is turned counter clock-wise through a quarter turn, bringing port 26 Vinto full registration with ports 18 and 24, as shown in Fig. 8; and during the last half of the exhaust stroke the disk 5 is turned clock-wise back into its former position shown in Fig. 7, thus completing the cycle. It will thus be seen that the disks a and b oscillate alternately'through a quarter circle to perform the intake and exhaust functions of the engine, respectively; each to-and-fro oscillatien occurring during one-fourth of the engine cycle.

nismo? The mechanism for operating the valves in the mannerabove described comprises a pair of reciprocatory 4cam-actuated rackbars meshing with pinions mounted on the respective valve stems, as will now be described. The upper end of valve stem 19 is equipped with a pinion 27, meshing `*with a rack-bar 28, mounted to reciprocate in a suitable guide-way 29. A similar pinion 31, fixed on the valve stem 22, is adapted to mesh with a similar rack-bar 32, mounted to reciprocate in a suitable guide-way 33. rlhe valves are maintained in operative position with their pinions meshing with their respective rack-bars, bymeans of a coiled expansion spring 34, bearing, at its opposite ends respectively, against a washer 35, on the upper end of the stem 22, and a ball-race member 36, supported through the intermediary of balls 37 and arcompanion race member38, from a rigid cross-bar 39.

The rack-bar 32, as will be evident from Fig. 4, is shaped at one end to provide an enlarged opening 41, which if preferred may be Vin the shape of an elongated slot through which the inner end of a cam-shaft 42 projects. The horizontal dimensions of the opening or slot are proportional to per- -mit reciprocation of the rack-bar without interfering with the cam-shaft 42 which projects therethrough. The rack-bar is further guided in its reciprocatory movements by the upper and lower guide-ways 43 and 44 in which the upper and lower flattened portions of the enlarged end of the rack-bar travel. The shaft 42, which is mounted in suitable brackets on the cylinder head, 'is continuously rotated by any suitable mechanism, and preferably is equipped with a sprocket wheel 45 adapted to be driven from any suitable source by a drive chain 46.

Upon the cam-shaft 42 there is fixedly secured, as shown in Fig. 4, a sharp cam 47, adapted to cooperate with a follower 48, carried by a pin 49, projecting laterally ,from the rack-bar. A complementary cam 50 fixed on the shaft 42 at the opposite side of the rack-bar, is adapted to coperate with a follower 51 carried by a pin 52, projecting in the opposite direction from the rackbar vhead, to positively move the rack-bar in the opposite direction from'that in which it is moved by the cam 47. The cam 50 is concentric throughout a major portion of its periphery, so that it will hold the rackbar and consequently the valve b stationary during three strokes of the engine piston, and the cam 47 had a sharp, short riser por` tion which opens the valve during the rst half `of the exhaust stroke, and said valve l'- i' is closed during the last half of the exhaust strokeV by the active side of the cam 50. 1t will thus be manifest that the valve b is positively opened by the` cam 47, and positively closed by the cam 50, with the result v tinguished from the yielding and uncertain action of spring-closed valves. 'lhe valve disks themselves, While show-n on the draw'- ings as being somewhat smaller in diameter than the cylinder head, may in actual practice be substantially of the same diameter as the cylinder, if preferred, and While the cylinder head is shown as having amachined depression of suficient .depth to accommodate both valve disks, the disks may ,in some instances be disposedbeneath the head Within the body of the cylinder. lin other Words the depth of the .depression may be varied Within Wide limits. When the disks are -Set wholly Within the depression as shovvn in Fig. 4: sudicient clearance should be left between the peripheries of the disks and the vertical Walls of the depression to take care of expansion of the disks and head and prevent sticking of. the valves.

rThe rack barl 28, lWhich actuatesthe valve q., is constructed substantially identical with the rack bar 32 and is guided inthe guideways 53 and tand equipped with a camv follower 55 adapted ,to be actuated by sharp cam 56, and With a follower 57 adapted to be actuated by the complementary cam 58. Cams 56 and 58 aremounted on a cam shaft 59 driven by a sprocket Wheel 6l through a chain 62. All of the mechanism for operating the valve a is substantially identical with thatvwhich operates valve 6. The cam 56 opens the valve a 'duri-ng the first half of the suction stroke, and said valve is closed during the last half of the suction stroke by the active side of the cam v58. h'igs. a and 5 illustrate therelative positions of the valve disks and of their operating eamsat the middle of the suction stroke of the engine piston.

From the foregoing it Will be apparent that the several ports controlling the intake consequently the intake and exhaust pase sages are at their maximum cross-sectional area, at mid-stroke of the engine piston when the volume of fluid Howing through said ports is at its maximum; the cross-sectional area being at its minimum during the initial and inalparts of the stroke vvhen the fluid displacement is least. I

The cam shafts 42 and 59 will extend across theheads of all the cylinders of the engine so that the valves o-,all the cylinders vvil be operated from these shafts. rlhe timing ot the valves ofthe various cylinders will be determined bythe position of the various cams on the shafts which cams should be properly adjustedthe same asthey must be on any gas engine.

lt will be manifest from the `foregoing that when the engine is in operation each valve disk vvill oscillate through an are ot approximately 90 degrees' through its opening and closing movements and that both valves remain stationary during the compression and ring strokes. lt Will also be obvious that each of the valve disks grinds its'own seat and that' the valves are held against their seats by the pressure Within the cylinder so that there is little possibility of leakage. Furthermore, since the valves arey stationary during the compression and ring strokes the friction and consequent Wear on vthe valves Will be'mueh less than it ison valves vvhich are moving under pressure, that is, valves which are .acted upon by the pressure Within the cylinder during their movenient..y

Many other advantages and desirable-v teatnres of my limproved valve mechanism Will be apparent'to those skilled in the art in addition to those above numerated andin addition to the fact that the valves are positively and accurately operated and that no reliance is placed upon springs or other uncertain mechanical elements. llt should also be understood that my invention is capable ot considerable modilicatio-n in its structural details Without departing 'trom thescope 'of the invention yas set forth in the following Claims.

l claim:

ll. ln a valve mechanism for gas engines, the combination of a plurality of valve diskseach provided vvith an inlet and an exhaust port, and means tor controlling said disks so that they both remain stationary during the compression and tiring strokes andere moved to aline the inlet and exhaust ports during the inlet and exhaust strokes respectively.

2. ln a valve mechanism for gas engines, the combination of a plurality ot' concentrically mounted oscillatory valve disks, each provided vvith an inlet and an exhaust port, means for maintaining said disks stationary and in closed position during the compression and iring strokes ot the engine, and means for moving said disks to open the inlet and exhaust ports at predetermined intervals.

3. ln a valve mechanism, for gas engines,

5. In a valve mechanism, the combination of' a plurality of concentrically mounted valve disks, pinions mounted on the valve stems, a rack bar meshing. with eachv pinion, and means for positively reciprocating said rack bars to oscillate saidrvalves in predetermined timed relation.

6. In a valve mechanism, the combination of a plurality of -concentrically mounted valve disks provided with inlet and exhaust ports and having valve stems projecting upwardly through the head of a cylinderL rack bars meshing with pinions on said stems, and means including a' plurality of positively actuated cams for reciprocating said rack bars to open and close said inletand exhaust ports.

y7. In a valve mechanism,"the combination of an oscillatory valved'lcc'imprising a'valve .disk and, a stem, a pinion on said stem, a rack bar meshing with said pinion, cam followers carried by said rack bar, a cam shaft, and a pluralityof cams mountedpon said shaft-to coperate with said followers whereby the rack bar 'is positively actuated inv both 'directions to oscillate said valve.

8. In a valve mechanism, the combination ofa valve comprising a disk and an integral valve stem rotatably mounted, a reciprocatory rack bar having a toothed connection withsaid stem, a cam shaft, and 4cam connections between said shaft and said rack,

bar wherebyY the rack baris intermittently reciprocated upon rotation of said shaft.

9. In ai valve mechanism, thecombinationof a plurality of valvev disks mounted to oscillate ,concentrically, a vplurality of cam" shafts, and vmeansl connecting said shafts with said valve disks whereby the disks are positively oscillated in alternating relation.

10. In a valve mechanism,` the combination of a pluralityrof rotatablvmountednoncentrically disposedA valvel disks, arecipro-V catory rack bar connected with each .disk and means for positively reciprocating said rackbars to oscillate said valves alternately.

at predetermined intervals. 11. In a valve mechanism for gas engines,

the combination with a -valve seat having inlet and exhaust ports, of a pairof super posed valves each having a pair 'of ports, one of said ports controlling. the inlet .and

f the other the exhaust functions of the n iech anism, means for moving one of said valves during the intake stroke, .and means .for

moving the other valve during the exhaust stroke, both of saidvalves remaining stationary during the compression and firing strokes.

i nected Awith vthe va .reciprocably for moving' the valve to closer and-open the port, a-pair of continuously 12. In a valve mechanism for-gas'engines, the combination with a circular valve seat having inlet and exhaust ports, of a pair of -superposed disk valves each having a pair of ports, one of Said valves controlling the inlet and the other the exhaust-functions of the mechanism, means for turning one of said valves during the intake stroke, and means for turning the other valve during the exhaust stroke, both of said valves remaining stationary during` the compression and firing strokes. y

13. In a valve mechanism for gas engines, the combination `with a circular valve seat having diametrically opposed inlet and exhaust ports, of alpair of superposed disk valves each having a pair of ports set quar- .tering, one of said valves controlling the inlet and theother the exhaust functions of they mechanism, positively actuated means for oscillating one of saiil` valves through a quarter turn during the intake stroke, and for oscillating. the other valve through a ouarterv turn during the exhaust stroke, both of said` valves remaining Istationary during the-compressin and `firing strokes.

14.111 a valve mechanism for gas engines,

' the .combination with a port communicating 15. In a valve mechanism -for gas engines,

the combination with a port communicating.

with an engine cylinder, of a valve movable with respect to the port for closing and opening jthe same, .and means for operatsaid. valve comprising ak member conve and being movable retatingpams', one of said cams being arrangedto move said member-and the valve to open the port and the other cam being arranged to move said member andvalve toI c loseA the port 'and to holdthe valve stationary in itsport-closingposition during the compression and irin strokes..

- I. CLINTO L. JOHNSON. Witnesses:

' `-JOHN H, MGCANNA, AST. JOHN.

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